Israel is to snub Poland's newly appointed education minister, accusing his far-right party of anti-Semitism.
Roman Giertych has insisted he and his party are not anti-Semitic
Roman Giertych heads the League of Polish Families (LPR), a nationalist party in Poland's coalition government.
But Israel has vowed not to deal with Mr Giertych, pointing to a long-held opposition towards LPR policies.
Poland's education ministry works closely with Israel organising visits by young Israelis to Holocaust-era sights across the country.
Israeli officials insisted their decision was consistent with decisions taken before the LPR joined Poland's government, and was not a personal snub to Mr Giertych.
"We will have no contact with the Polish education minister, who heads a party with an anti-Semitic platform," a spokeswoman told the AFP news agency.
Mr Giertych attempted to defuse the issue by laying flowers at the site of massacre of Jews 65 years ago during World War II.
Visiting Jedwabne, where hundreds of Jews were rounded up and burned alive in July 1941, Mt Giertych denied Israel's interpretation of his party's policies.
"There is and will be no place for anti-Semitism in Poland," he said.
"I like the Jewish nation and I can't see a reason why the ambassador doesn't like me."
Israel's ambassador to Poland, David Peleg, had already dismissed Mr Giertych's visit to Jedwabne, saying there would not change official policy towards the LPR.
Israel fears that any substantial role for the LPR within the government of Polish President Lech Kaczynski could hamper the president's stated aim of combating anti-Semitism within the country.
The LPR has historic links with a now-defunct party that promoted limits on Jews and segregation in pre-war Poland.
There are also concerns over the LPR's youth wing, the All-Polish Youth, whose members have given Nazi salutes and slogans.
Almost all of Poland's estimated three million Jews were killed during the Nazi Holocaust of World War II.
Each year thousands of young Israelis travel to Poland to visit Nazi death camps, concentration camps, and towns and cities of historic importance.